1. Field of the Invention
The present invention relates to, for example, a semiconductor device, a display device, a light-emitting device, a security device, an imaging device, a driving method thereof, or a manufacturing method thereof. Particularly, the present invention relates to, for example, a light-emitting device or an information processing device.
2. Description of the Related Art
The social infrastructures relating to means for transmitting information have advanced. This has made it possible to acquire, process, and send out many pieces and various kinds of information with the use of an information processing device not only at home or office but also at other visiting places.
In such a situation, portable information processing devices are under active development.
An organic EL element can be formed into a film shape; thus, a large-area element can easily be formed. Therefore, the organic EL element has a high utility value as a surface light source that can be applied to lighting or the like.
For example, Patent Document 1 discloses a lighting device including an organic EL element.